Safety and efficacy of full-dose apixaban vs rivaroxaban for cancer-associated venous thromboembolism in patients with solid tumors: A real-world study.

e23439 Background: Cancer-associated venous thromboembolism (CA-VTE) is a major cause of morbidity and mortality in patients with active malignancy, and direct oral anticoagulants (DOACs) are increasingly used for the treatment. We evaluated recurrent VTE and bleeding outcomes in patients with active solid tumors treated with apixaban (API) 5 mg or rivaroxaban (RIV) 20 mg. Methods: Using the TriNetX research network, we identified adults with colon, breast, lung, prostate, head and neck, or pancreatic cancer and active disease, defined by receipt of chemotherapy, radiation, or cancer surgery within 6 months of cancer diagnosis. We excluded patients with hematologic malignancies, myelodysplastic syndromes, atrial fibrillation, or pregnancy within 6 months of the cancer index date. Eligible patients had a diagnosis of acute deep vein thrombosis (DVT) or pulmonary embolism (PE) within 30 days of the cancer index date. They were treated with API 5 mg (excluding any RIV and API 2.5 mg) or RIV 20 mg (excluding any API and RIV 2.5 or 5 mg). Propensity score matching (1:1) was performed on demographics, comorbidities (including CKD and ESRD), hemoglobin, and thrombocytopenia. The primary outcome was recurrent DVT or PE at 1 year. Secondary outcomes included all-cause mortality (ACM), intracranial hemorrhage (ICH), gastrointestinal (GI) bleeding, anemia, and blood transfusion (BT). Results: After matching, 5,690 patients were included per cohort. At 1 year, recurrent PE occurred in 4.32% vs 4.38% (hazard ratio [HR] 1.02, 95% CI 0.73–1.43; log-rank p = 0.89), and recurrent DVT occurred in 6.57% vs 5.12% (HR 1.34, 95% CI 1.07–1.68; log-rank p = 0.009) in the API and RIV groups, respectively. ACM was higher with API (30.0% vs 24.5%; HR 1.31, 95% CI 1.22–1.41; log-rank p < 0.0001). Anemia (15.1% vs 13.9%; HR 1.15, 95% CI 1.02–1.30; log-rank p = 0.022) and BT (6.68% vs 5.76%; HR 1.20, 95% CI 1.03–1.41; log-rank p = 0.016) were also more frequent in the API cohort. ICH and GI bleeding rates were similar. Conclusions: In this real-world cohort of patients with active solid tumors and CA-VTE, full-dose API and RIV had similar 1-year risks of recurrent PE, GI bleeding, and ICH. RIV was associated with lower rates of recurrent DVT, all-cause mortality, anemia, and transfusion. Given the observational design and potential residual confounding, these results are hypothesis-generating and highlight the need for prospective head-to-head trials.